Yasu told the emissary of Pegasus that she has laid the foundation for a New Hope populated by sunflowers, again connecting to Sekai. It seems to me like Sekai/Pareidolia are trying to corrupt Yasu's church and use it for their own purposes.
And who do we have visiting the church:
Sensei: has Sekai/Pareidolia inside of him
Kaori: has Sekai/Pareidolia inside of her
Sana: Pareidolia has been fucking with her mind and probably isn't done, given her rapid personality shift in Chapter 4
Nodoka: has apparently been receiving instruction/information from The World/Sekai
That leaves Touka as the odd one out. The Emissary of Pegasus did demand a sacrifice...
Given when daisy bell usually plays, and the freelancers being confirmed as "children of the clockwork", I think we can add "daisy bell" as another one of the evidences of the cycles being a sort of simulation.
I mean that it should be added with "users", "terminals", "templates", and stuff like that when we discuss it - it doesn't seem like the first ever song to be "sang" by a computer being there when we're dealing with "supernatural" things would be a coincidence.